Catography in a Crisis
This shows the actual path that Cyclone Nargis took,’ says Ian Howard-Williams from the UK’s Department for International Development (DFID), pointing to a multi-coloured line snaking its way over a satellite image of the Bay of Bengal. ‘We had been watching it when it was just a tropical storm and were obviously concerned because it was heading for Bangladesh. But by Thursday night, it changed direction and we all knew what it was going to do.’
When Cyclone Nargis struck Myanmar last year, it resulted in the worst natural disaster in the nation’s recorded history. At 4pm local time on 2 May, a swirling mass of dense cloud and winds of up to 215km/h made landfall near the mouth of the Irrawaddy River, driving a devastating tidal surge inland with it. The low-lying, fertile Irrawaddy region – Myanmar’s ‘rice bowl’ – was inundated as Nargis continued its northeasterly path, passing close to the country’s largest city, Yangon, before dissipating near the Thai border less than 24 hours later. Some 700,000 homes were destroyed and two million people left homeless.
The precise number of fatalities is still not known (estimates vary between 80,000 and 146,000), but the death toll could have been significantly lower had the world’s aid agencies been granted entry into Myanmar. For eight days after the initial impact, the country’s military rulers barred entry to almost all international disaster relief specialists and effectively blocked aid – a situation that was condemned around the world, prompting Prime Minister Gordon Brown to denounce the ‘inhuman treatment of the Burmese people’.
While they tried to get visas, Howard-Williams and the rest of the Humanitarian Preparedness and Response Team monitored the situation via the DFID Myanmar office in Yangon. Normally, the team would arrive at the disaster zone within a day or two. ‘We got there eight days after the cyclone, but we had already started to get an idea of where had been hit the worst and what the most pressing issues were,’ says Deborah Baglole, team leader of DFID’s Cyclone Nargis response team. ‘We were able to set up our team within the Myanmar office, get hold of downloaded maps and other useful local information and work out what we were going to do.’
Mapping the emergency
When a natural disaster occurs, the response from aid agencies typically follows a prescribed chain of events. The first phase involves search and rescue, which tends to last for around two to three days, followed by a ‘needs assessment’ of aid.
‘It’s during the assessment and early relief phases that there is a need for basic information about the emergency,’ explains Nigel Woof from MapAction, a small NGO that describes itself as ‘the blue-light service of the mapping world’, providing mapping and other geospatial information disasters. ‘Many of the questions that arise are about the extent or geography of the disaster. There can be an awful lot of mistakes made if there is a lack of under-standing about where an actual disaster is, where those affected by it are, where the resources are and how to reach the affected people with those resources.’
Maps, aerial photography and satellite imagery are critical, if not vital, for navigation in an emergency, but their real power is in their ability to communicate and share complex information about an ever-changing situation among the different agencies involved. For Baglole and her team, maps enable them to make an assessment of the situation and then make recommendations to NGOs and
UN agencies working in the region and channel funds accordingly.
‘It all happens so quickly,’ says Baglole. ‘You’re coming together with your assessments of what’s needed and working out who’s well placed to do that as soon as possible.’ Without maps, this would be virtually impossible, she says. ‘We have to be able to quantify the situation – quickly – even if that means using pins on a wall map in the absence of decent maps.’
Making sense of an emergency
The cartographers that work in emergency situations are often present in the early stages following a natural disaster, providing field-level mapping support. The quality and complexity of the maps they supply can vary, from ‘low-tech’ photocopied maps of a particular region to help relief workers get their bearings on arrival or satellite images showing areas that have perhaps been flooded following a tsunami or cyclone, to a sophisticated computer-based geographical information system (GIS) map containing a very high level of detail. The beauty of GIS is that it can be updated to help aid agencies understand the scale of the challenge and keep tabs on the movement of hundreds, thousands or even hundreds of thousands of people, medical supplies, tents and food.
But to build a good GIS, you need an excellent source of base maps and, sadly, many areas that are vulnerable to natural disasters fall within the boundaries of developing countries, where such material is often lacking. ‘There are many places in the world where the government simply doesn’t have the resources [to fund surveys and the production of new maps] so, in those cases, we have to do the best that we can with whatever we can get our hands on,’ says Woof.
Before deployment to a disaster zone, the first thing MapAction workers will do is conduct a so-called ‘data scramble’ of the area involved. This essentially means finding out what kind of map data is out there to import into the GIS. ‘There are dozens of different potential sources – some more conventional (and up-to-date) than others,’ says Woof. ‘In the early days, you just have to go with what you’ve got and that will have to do,’ agrees Howard-Williams (See Less conventional maps).
In the case of Cyclone Nargis, the MapAction team (who worked remotely from a base in Bangkok due to the difficuty obtaining visas) used two components for the vital base maps on which to build more detailed and sophisticated GIS maps: UNOSAT satellite imagery and, perhaps surprisingly, maps produced in 1944 by the Directorate of Colonial Surveys during the British occupation of Burma.
‘Although this mapping data was from the 1940s, it was still incredibly useful,’ says Woof. ‘One of our team members out in the field later reported that it correlated closely with modern-day Myanmar – very few places had moved.’
A sketch map, but a good map
The magnitude-6.5 earthquake that stuck the Iranian city of Bam in 2003 perhaps illustrated the need for good-quality maps even more profoundly. In the immediate aftermath, search-and-rescue teams had
to make do with a lone hand-drawn map of the city centre that had been copied from a tourist guide.
‘There were no street maps of Bam,’ says Howard-Williams. ‘It’s a very old city that’s fairly remote. After the event, we got a fair amount of satellite imagery, but probably not for a week after, which is no use if you’re there on the ground trying to dig people up within 24 hours.’
The earthquake damage, which resulted in the deaths of up to 40,000 people, was exacerbated by the fact that large parts of Bam were historic adobe buildings that didn’t comply with earthquake regulations set by the government. And the lack of decent GIS mapping data also caused problems in the initial damage and needs assessments.
‘The sketch map was quite a good map, but there was no means of replicating it, which meant that the search-and-rescue teams were unable to accurately define the area that they had searched,’ explains Woof. ‘Instead [of marking up a map], they put ground markers in areas that had been assessed. But it was very cold, particularly at night, and all the people who had lost their homes were looking for anything to burn – so these markers were invariably pulled out. This was a classic example of the need and the potential for using GIS-based rapid mapping methods in disasters.’
The future of emergency maps
The use of GIS software in the field has only been practical for the past five or six years. Before then, laptops didn’t have the power or memory capacity to support this kind of complex software, and it would have been impractical to transport desktop computers into the field. The main drawback of GIS is that it requires extensive training to use, which is why mapping specialists are in demand after a natural disaster. But, as map-sharing portals such as Google Earth gain greater sophistication and use in emergencies, could GIS specialists soon disappear in relief efforts?
‘The next big evolution in humanitarian mapping will be through a new generation of websites that will be more collaborative, a bit like Facebook and Twitter, except that in our case, geospatial information will be exchanged,’ says Woof. ‘There’s definitely a convergence going on among the highly technical, previously inaccessible, highly specialist tools in the GIS world. In the future, it will be about having a wider range of tools, which can be used by everyone – much like Google Earth. We’ll spend less time making maps, but more time managing bigger shovels-full of spatial data.’
September 2009
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